Recent debates on insect decline require sound assessments on the relative drivers that may negatively impact insect populations. Often, baseline data rely on insect monitorings that integrate catches over long time periods. If, however, effects of time-critical environmental factors (e.g., light pollution) are of interest, higher temporal resolution of insect data is required during very specific time intervals (e.g., between dusk and dawn). Conventional time-critical insect trapping is labour-intensive (manual activation/deactivation) and temporally inaccurate as not all traps can be serviced synchronically at different sites. Also, temporal shifts of environmental conditions (e.g., sunset/sunrise) are not accounted for. We present a battery-driven automated insect flight-interception trap which samples insects during seven user-defined time intervals. A commercially available flight-interception trap is fitted to a turntable containing eight positions, seven of them holding cups and one consisting of a pass-through hole. While the cups sample insects during period of interest, the passthrough hole avoids unwanted sampling during time-intervals not of interest. Comparisons between two manual and two automated traps during 71 nights in 2018 showed no difference in caught insects. A study using 20 automated traps during 104 nights in 2019 proved that the automated flight-interception traps are reliable. The automated trap opens new research and application possibilities as arbitrary insect-sampling intervals can be defined. The trap proves efficient, saving manpower and associated costs as activation/deactivation is required only every seven sampling intervals. In addition, the timing of the traps is accurate, as all traps sample at exactly the same intervals and ensure comparability. The automated trap is low maintenance and robust due to straightforward technical design. It can be controlled manually or via smartphone through a Bluetooth connection. Full construction details are given in Appendices.

12Recent debates on insect decline require sound assessments on the relative drivers that may negatively 13 impact insect populations. Often, baseline data rely on insect monitorings that integrates catches over 14 long time periods. If, however, effects of time-critical environmental factors (e.g., light pollution) are 15 of interest, higher temporal resolution of insect observations during specific time intervals are required 16 (e.g., between dusk and dawn). Conventional time-critical insect trapping is labour-intensive (manual 17 activation/deactivation) and temporally inaccurate as not all traps can be serviced synchronically at 18 different sites. Also, temporal shifts of environmental conditions (e.g., sunset/sunrise) are not 19 accounted for. 20 We provide a battery-driven automated insect flight-interception trap which samples insects during 21 seven user-defined time intervals. A commercially available flight-interception trap is fitted to a 22 157 (e.g., https://www.msr.ch/en/product/msr145 for lux, temperature and relative humidity 158 measurements). 159 160